I hope it's just a joke :x the site you are visiting is OF Hercules emulator. So he clearly means edit the emulator files.You need to edit src/common/mmo.h,
Find PACKETVER and change it to the client date you have chosen.
Yeah I don't know where that is, I cant even get close to finishing the hercules setup because the instructions are outdated and mostly have dead links. And it just turned me off to making my own server for my Lan.
I think I was confused the same when I was trying to get my head around how RO emulation works.
RO runs off the server files provided in the Hercules github.
I think this thread is the perfect place to get started. If you can set your server up through this guide, it's a huge learning step. I probably couldn't set a server up this way even now, but I did it once and it got me started. Now everything is a lot easier and I know my server files like the back of my hand.
How do you start doing the hercules setup? Im really new to all this.